Cooling System for Actuator

ABSTRACT

An actuator wherein an internal coolant line or chamber extends through both the housing member and the cover member of the actuator. Each of the coolant chambers terminates in a pair of ports. In one embodiment, an external line connects one of the ports in the housing member with one of the ports in the cover member and the other of the ports in the housing member and the cover member are adapted for coupling to respective external coolant input and output lines respectively. In one embodiment, each of the coolant chambers is a generally U-shaped internal conduit.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date and disclosure ofU.S. Provisional Application Ser. No. 61/307,485, filed on Feb. 24, 2010and is a continuation-in-part application of U.S. application Ser. No.12/785,844 filed on May 24, 2010, the disclosures of which areexplicitly incorporated herein by reference as are all references citedtherein.

FIELD OF THE INVENTION

This invention relates generally to actuators and, more specifically, toa system for cooling an actuator.

BACKGROUND OF THE INVENTION

This invention relates to actuators which are used in a wide variety ofapplications to move, actuate, or rotate a part such as, for example, avalve or a switch.

Current actuator designs such as, for example, the actuator design shownin FIG. 1 of this application incorporate a system for removing the heatgenerated by the motor and circuit board components of the actuator aswell as the heat generated by components surrounding the actuator suchas, for example, the heat generated by the gas flowing through an EGRvalve coupled to the actuator.

As shown in FIG. 1, the actuator 10 depicted therein and of the typedisclosed in U.S. Published Patent Application No. US 2010/0301691 iscomprised of two main components, i.e., a housing member 12 and a covermember 14 coupled to each other and together defining an interior cavity(shown in U.S. Published Patent Application No. US 2010/0301691) inwhich all of the actuator elements are located such as, for example, themotor, the gears, and the electronics. The housing member 12incorporates an internal cooling system 16 defined by an elongate,internal cooling chamber or line or conduit 18 unitary and internal withthe housing member 12 and terminating in a pair of ports 20 and 22defined in a top surface or wall 24 of the housing member 12.

Although not shown in great detail in FIG. 1, it is understood that theinternal cooling conduit 18 includes a pair of spaced-apart, parallel,and generally vertical conduit segments 18 a (only one of which is shownin FIG. 1) with respective upper ends terminating in the respectiveports 20 and 22 and a generally horizontal conduit segment (not shown)extending between and joining the lower ends (not shown) of the verticalconduit segments 18 a to define a generally U-shaped internal coolingconduit 18.

An external coolant input line or conduit 23 is coupled to the port 22and an external coolant outlet line or conduit 23 is coupled to the port20. A coolant such as, for example, water or antifreeze flows into theactuator 10 from the external coolant input line 23, through the port22, down through the internal line or conduit 18, up through the outletport 20, and out through the external coolant outlet line or conduit 21.

However, in applications such as, for example, the application where theactuator 10 is coupled to the shaft of an EGR valve, heat radiateseither from the EGR valve through the shaft/valve interface or from theexhaust manifold and heats the cover member 14 of the actuator 10 beforereaching the housing member 12 of the actuator 10.

The present invention is directed to an improved actuator cooling systemin which heat is removed from the cover member of the actuator beforereaching the housing member and the internal components of the actuator.

SUMMARY OF THE INVENTION

The present invention is directed to an actuator which comprisesrespective housing and cover members including respective internalcoolant lines or chambers. Each of the coolant lines or chambersterminates in a pair of ports in the housing and cover membersrespectively.

In one embodiment, an external line interconnects one of the ports inthe housing member with one of the ports in the cover member. In thisembodiment, an external coolant input line is adapted for connection tothe other one of the ports in the housing member and an external coolantoutput line is adapted for connection to the other one of the ports inthe cover member.

In another embodiment, respective external coolant input and outputlines are adapted to be connected to the pair of ports in the housingmember and cover member respectively.

In one embodiment, each of the coolant chambers includes first andsecond spaced-apart conduit segments with respective first ends whichterminate in the pair of ports in the housing and cover membersrespectively, and a third conduit segment which extends between andinterconnects the second ends of the first and second conduit segmentsto define respective generally U-shaped coolant chambers.

There are other advantages and features that will be more readilyapparent from the following description of the invention, the drawings,and the appended exemplary claims.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings that form a part of the specification:

FIG. 1 is a perspective view of the current design of the cooling systemof an actuator; and

FIG. 2 is a perspective view of one embodiment of an actuatorincorporating the cooling system of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is susceptible to embodiment in many differentforms, this specification and the accompanying drawings disclose oneform of the subject actuator as an example of the invention. Theinvention is not intended to be limited to the embodiment so described,however. The scope of the invention is identified in the appendedclaims.

An actuator 100 in accordance with the present invention is shown inFIG. 2. Actuator 100, which is of the type disclosed in U.S. PublishedPatent Application No. US 2010/0301691, comprises two main components: ahousing member 112 and a cover member 114 which is coupled to thehousing member 112 and together define an interior cavity or chamberwhich houses the various elements of the actuator 100 including, forexample, the motor, the gears, and the electronics as shown in, forexample, U.S. Published Patent Application No. US 2010/0301691.

The housing member 112 includes a cooling system 116 defined by anelongate internal cooling chamber or line or conduit 118 which, in theembodiment shown, is formed as part of and unitary with the casting forthe exterior wall of the housing member 112. In the embodiment shown,the conduit 118 terminates in a pair of co-linearly aligned,spaced-apart ports 120 and 122 defined in a top face or wall 124 of thehousing member 112.

Although not shown in detail in FIG. 2, it is understood that theinternal cooling conduit 118 is similar to the internal cooling conduit18 shown in FIG. 1 and includes a pair of spaced-apart, parallel andgenerally vertical conduit segments 118 a (only one of which is shown inFIG. 2) having respective upper ends thereof terminating in therespective ports 120 and 122 and a generally horizontal conduit segment(not shown) extending between and joining the lower ends (not shown) ofthe vertical conduit segments 118 a to define a generally U-shapedinternal cooling conduit 118.

In accordance with the present invention, the cover member 114 likewiseincludes a cooling system 126 defined by an elongate internal coolingchamber or line or conduit 128 which, in the embodiment shown, is alsoformed as part of and unitary with the casting for the exterior wall ofthe cover member 114. The conduit 128 terminates in a pair ofco-linearly aligned, spaced-apart ports 130 and 132 in a top face orwall 134 of the cover member 114.

More specifically, and although not shown in detail in FIG. 2, it isunderstood that the internal cooling conduit 128 includes a pair ofspaced-apart, parallel and generally vertical conduit segments 128 ahaving respective upper ends thereof terminating in the respective ports130 and 132 and a generally horizontal conduit segment (not shown)between and joining the lower ends (not shown) of the vertical conduitsegments 128 a to define a generally U-shaped internal cooling conduit128 extending through the exterior wall of the cover member 114.

In the embodiment shown, the top face or wall 124 of the housing member112 and the top face or wall 134 of the cover member 114 are generallyco-planar; the port 120 in the top face or wall 124 of the housingmember 112 is spaced from, and co-linearly aligned with, the port 130 inthe top face or wall 134 of the cover member 114; and the port 122 inthe top face or wall 124 of the housing member 112 is spaced from, andco-linearly aligned with, the port 132 in the top face or wall 134 ofthe cover member 114.

In one embodiment of the present invention as shown in FIG. 2, agenerally U-shaped external line or conduit 140 extends between andincludes one end coupled to the port 120 on the housing member 112 andan opposite end coupled to the port 130 on the cover member 114.

Further, in accordance with this embodiment, a first external coolantinput or supply line or conduit 121 includes one end coupled to the port122 of the housing member 112 and a second external coolant output lineor conduit 123 includes one end coupled to the port 132 on the covermember 114.

Thus, in accordance with the invention as shown in FIG. 2, a liquidcoolant such as, for example, water or antifreeze and generallydesignated by the arrow 150 in FIG. 2, is introduced and enters into theactuator 100 via and through the external input conduit 121 and into theport 122; flows down through the internal conduit 118 in the housingmember 112 and, more specifically, successively down through thevertical conduit segment 118 a thereof, then horizontally through thelower horizontal conduit segment thereof (not shown), and then upthrough the other vertical conduit segment thereof (not shown), then upthrough the port 120 into and through the external conduit 140; theninto and down through the port 130; then down through the internal lineor conduit 128 in the cover member 114 and, more specifically,successively down through the first vertical conduit segment 128 a, thenhorizontally through the lower horizontal conduit segment (not shown),and then upwardly through the second vertical conduit segment 128 a; andthen the coolant, generally designated by the arrow 152 in FIG. 2, exitsthe actuator 100 through the port 132 in the cover member 114 and upthrough the exterior outlet conduit 123.

Thus, in accordance with the present invention, the incorporation of aninternal coolant line or chamber or conduit 128 in the cover member 114which is coupled to the internal conduit 118 in the housing member 112advantageously allows heat generated on the cover member 114 side of theactuator 100, such as the heat generated by the gas flowing through anEGR valve coupled to the actuator 100 via a shaft (not shown) extendinginto the cover member 114, to be removed on the cover member 114 side ofthe actuator 100 rather than being allowed to flow through the covermember 114 and into the housing member 112 and internal components as inthe actuator 10 shown in FIG. 1.

Numerous variations and modifications of the embodiment described abovemay be effected without departing from the spirit and scope of the novelfeatures of the invention. It is to be understood that no limitationswith respect to the specific cooling system illustrated herein areintended or should be inferred. It is, of course, intended to cover bythe appended claims all such modifications as fall within the scope ofthe claims.

For example, it is understood that, in lieu of the external line 140shown in FIG. 2, two separate sets of external coolant input and outletlines or conduits (not shown) can be coupled to the housing member ports120 and 122 and the cover member ports 130 and 132 respectively tocreate two separate and independent closed loop cooling systems, i.e.,one in the housing member 112 and another in the cover member 114, eachincluding respective cooling systems 116 and 126 and respective internalcooling chambers 118 and 128 identical in structure to those shown inFIG. 2.

1. An actuator comprising respective housing and cover members includingrespective coolant lines.
 2. The actuator of claim 1 wherein each of therespective coolant lines is internal to the housing and cover membersand terminates in a pair of ports in the housing and cover membersrespectively.
 3. The actuator of claim 2 wherein an external coolantline interconnects one of the pair of ports in the housing member withone of the pair of ports in the cover member.
 4. The actuator of claim 3wherein an external coolant input line is coupled to the other one ofthe pair of ports in the housing member and an external coolant outputline is coupled to the other one of the ports in the cover member. 5.The actuator of claim 2 wherein an external coolant input line and anexternal coolant output line are coupled to the pair of ports in thehousing and cover members respectively.
 6. The actuator of claim 2wherein each of the respective coolant lines is generally U-shaped andincludes respective first and second spaced-apart segments terminatingin the pair of ports and a third segment interconnecting the lower endsof the first and second segments.
 7. An actuator comprising: a housingmember including a coolant chamber terminating in a pair of ports; acover member including a coolant chamber terminating in a pair of ports;and an external line extending between and interconnecting one of theports in the housing member and one of the ports in the cover member. 8.The actuator of claim 7 wherein each of the coolant chambers in each ofthe housing and the cover members includes first and second spaced-apartand generally parallel conduit segments including respective first endsterminating in the pair of ports and respective second ends connected toa third conduit segment extending between the first and second conduitsegments.
 9. The actuator of claim 8 wherein each of the coolantchambers is generally U-shaped.